From the second or third century A.D., it has been known that silver exhibits an antibacterial effect and, therefore, silver products have been employed as tableware including silver plates. To make one's living environment more hygienic and healthy using such an antibacterial action of the metal capable of performing ion exchange, a variety of antibacterial products or goods have been hitherto proposed. For example, the Japanese Laid-Open Patent Publication (unexamined) No. Hei 6-297629 discloses an antibacterial cloth.
The antibacterial cloth according to this prior art comprises: an inner layer member of which water absorbing performance is improved by mixing an inorganic antibacterial agent containing copper ion, etc. into an urethane foam resin; and a cloth-like outer layer member composed of a cotton yarn serving as a weft formed by entangling an extra fine metallic yarn of copper or the like and a rayon yarn serving as a warp.
However, following problems exist in the mentioned antibacterial cloth.
First, since the extra fine metallic yarn is employed, the antibacterial cloth is heavy and hard. Further, the extra fine metallic yarn is easy to cut, and therefore it is difficult to wash the cloth to use it repeatedly, and there may arise a further problem of injuring a user due to the cut metallic yarn.
If the mentioned extra fine metallic yarn is incorporated as a warp, there arise disadvantages such that the yarn is easy to cut, making it difficult to warp and weave the yarn, and the resultant cloth itself becomes hard due to hardness of the metal, and therefore the extra fine metal can be used only as a weft. Even used only as a weft, the metallic yarn is not resistant to a high speed weave or fabrication, which results in a low productivity, and since the surface of the cloth is coated with the extra fine metallic yarn, the water absorbing property of the cellulosic fiber yarn is sacrificed, eventually affecting the deodorizing performance.
Moreover, in spite of the necessity of keeping the antibacterial cloth in contact with an object continuously for a certain time in order that the antibacterial cloth exhibits an antibacterial performance, there is no consideration about the proper wrapping of a food with such an antibacterial cloth in the aforementioned patent publication. It is stated in the patent publication that when using the antibacterial cloth, an effect is instantaneously produced. It is, however, known from some experimental data that any sufficient antibacterial effect is not exhibited without keeping continuously for a certain time the antibacterial cloth in contact with a portion where antibacterial effect is expected. If any antibacterial effect is exhibited on the water or dust wiped out from the portion where the antibacterial cloth contacts, it is useless and means nothing.
Accordingly, an object of the invention is to provide food wrapping cloth in which antibacterial and sterilizing effect is sufficiently performed, and which is soft, light and capable of being used repeatedly.